The present invention relates to a motor driving device and method for a vehicle, and more particularly to a technology for controlling and diagnosing an air-conditioning motor by sensing an output signal and a current of a feedback sensor. Generally, a Heating, Ventilation, and Air Conditioning (HVAC) system that adjusts indoor temperature of a vehicle and implements a more comfortable or pleasant environment is mounted within the vehicle. Recently, Full Automatic Temperature Control (FATC) systems configured to maintain a comfortable environment by automatically adjusting indoor temperature according to a setting temperature selected by a vehicle driver or passenger are embedded in many vehicles.
In accordance with the FATC system, when a driver or passenger within the vehicle in which the FATC system is mounted selects a setting temperature, an air-conditioning controller (i.e., FATC controller) is configured to receive sensor detection signals from various sensors used for adjusting indoor temperature, for example, a solar-radiation sensor configured to detect the amount of solar radiation, an outdoor-temperature sensor configured to detect outdoor temperature, and an indoor-temperature sensor configured to detect indoor temperature of the vehicle, so that the FATC system can efficiently adjust indoor temperature of the vehicle. The FATC system may be configured to calculate thermal load of an indoor space based on detection values of various sensors. The FATC system is also configured to determine a discharge mode, a discharge temperature, a discharge direction, a discharge airflow, etc.
To adjust indoor temperature and system operations, the FATC controller is configured to receive detection values from a discharge-temperature sensor configured to detect a discharge temperature, a heater temperature sensor configured to detect a temperature of an electric heater (e.g., a positive temperature coefficient (PTC) heater) (i.e., an auxiliary heater in case of an internal combustion engine vehicles, and a main heater in case of an electric vehicle), and an evaporator temperature sensor configured to detect an evaporator temperature. Further, to adjust the supply of the air-conditioning air according to the determined discharge mode, the determined discharge temperature, the determined discharge direction, and the discharge airflow, a mode actuator, a temperature door (i.e., a temperature control door), an actuator, an actuator, a fan-control-door actuator, an air-conditioning blower, a compressor, an electric heater, etc. are controlled.
FIG. 1 is an exemplary equivalent circuit of a conventional air-conditioning motor device according to the related art. Referring to FIG. 1, the conventional air-conditioning motor device includes a motor M, a motor driver 10, and a feedback sensor 20. The motor driver 10 is configured to output a drive voltage to drive the motor M upon receiving a power-supply voltage VCC. The feedback sensor 20 is configured to detect a driving angle of the motor M and output the detected driving angle as a voltage value. The feedback sensor 20 may be driven by a reference voltage (Ref) (for example, about 5V).
FIG. 2 is an exemplary schematic diagram illustrating the conventional air-conditioning motor device that operates in a normal mode according to the related art. In FIG. 2, it may be assumed that a target drive voltage of the motor M is set to 4V. When a voltage detected by the feedback sensor 20 is set to 4V, the controller 30 is configured to feed back a target position of the motor M in response to an output signal of the feedback sensor 20.
FIGS. 3 to 5 illustrate exemplary cases in which a faulty operation or malfunction occurs in the conventional air-conditioning motor device. Referring to FIG. 3, when an abnormal stall occurs in the motor M having a target voltage of 4V, the sensing voltage of the feedback sensor 20 may be detected as a voltage of 3V. Although the motor M of the conventional air-conditioning motor device is stalled, a drive current may be continuously applied to the motor M.
Referring to FIG. 4, although a target voltage of the motor M is set to 4V, when a terminal for interconnecting the motor M and the controller 30 is severed or cut off, the sensing voltage of the feedback sensor 20 may be set to 3V. When a broken wire or a disconnection part occurs in the motor M, the motor M does not move to a target position. The conventional air-conditioning motor device is designed to apply a drive current to the motor M during a predetermined time (e.g., about 10 seconds) even when a wire of the motor M is opened.
Referring to FIG. 5, although the motor M has a target voltage of 4V, when a terminal for interconnecting the motor M and the controller 30 is short-circuited, the sensing voltage of the feedback sensor 20 may be detected as another voltage. When the motor M is short-circuited, the motor M does not move to the target position. The conventional air-conditioning motor device is designed to apply a drive current to the motor M during a predetermined time (e.g., about 10 seconds) even when a wire of the motor M is short-circuited.
As described above, a faulty operation or malfunction may occur in the motor M due to various reasons such as an abnormal stall, short-circuiting, a broken wire, etc. However, the conventional air-conditioning motor device determines a state of the motor M using only the output value of the feedback sensor 30.
In particular, it may be difficult for the conventional air-conditioning motor device to correctly recognize whether a control error of the motor M occurs due to an abnormal stall, a broken wire, or short-circuiting, as shown in FIGS. 3 to 5. Accordingly, a drive current is applied to the conventional air-conditioning motor device during a timeout interval and the drive current may unavoidably affect durability of the motor and constituent components thereof, so that the conventional air-conditioning motor device may have difficulty in correctly recognizing the actual failure mode.